Make chat limit 30.
Make chat limit 30.

This aligns it with the limit meatspace previously had. 15 seems to be
way too few with the larger videos, very hard to follow conversations.

harlo/meatspace-chat-v2,harlo/meatspace-chat-v2,renrutnnej/meatspace-chat-v2,renrutnnej/meatspace-chat-v2